Chinook

The Chinook CH-47 helicopter is named after the Pacific Northwest “Chinook” Native Americans that were non-nomadic and lived in long cedar plankhouses. The helicopter was developed by Boeing Vertol and designs as early as 1957 were started but the YHC-1B made it’s initial hover flight on September 21, 1961. The Chinook CH-47, as it is known today, is still in production and 1,179 have been built to date. Boeing Rotorcraft Systems is the current manufacturer and the cost of each aircraft is $35 million.
Chinook HC-1B HC-1B in flight during testing and evaluation.

In 1962 the HC-1B was redesignated the CH-47A and was named “Chinook”.
Initially the CH-47 was powered by two 2,200 hp turboshaft engines, mounted on each side of the helicopter’s rear end and connected to the rotors by driveshafts. Currently models are fitted with engines of 4,733 hp. The CH-47 uses counter-rotating rotors which eliminate the need for an anti-torque vertical rotor, allowing all power to be used for lift and thrust. The ability to adjust lift in either rotor makes it less sensitive to changes in the center of gravity, important for the cargo lifting role. If one engine fails, the other can drive both rotors.
The US Army adopted the CH-47 as it’s standard medium transport helicopter and by November 29, 1965 it had arrived and was in use in Vietnam.
The Chinook has a cavernous 42 cubic meter cargo bay which can accomodate 33-55 troops.
Chinooks were sometimes used for casualty evacuation but due to very heavy demand for the helicopters they were usually overburdened with wounded beyond the 24 litter norm.
The Army soon learned that the CH-47 would be invaluable for artillery and heavy logistics movement to the point that it was seldom used as an assault troop carrier.
The Chinook uses a triple hook external payload system providing stability to large or multiple external loads. Artillery equipment such as 155mm howitzers could be transported to remote positions (which would be inaccessible by any other means) and then resupplied with food, equipment, and ammunition. Multiple external loads could also be delivered to two or three separate destinations in one sortie. Downed aircraft recovery is also possible with this system.
The modern CH-47F has a 21,000 lb load capability (nearly twice the Chinook’s original lift capacity) and a 26,000 lb center sling load capacity.
21 countries currently operate CH-47 Chinooks today.

Specifications CH-47 Chinook

• Crew: 3 (pilot, copilot, flight engineer)
• Capacity: 28,000 lb (12,700 kg) cargo, or 33–55 troops, or 24 litters and 3 attendants
• Length: 98 ft 10 in (30.1 m)
• Rotor diameter: 60 ft 0 in (18.3 m)
• Width: 15 ft 9 in (4.80 m) (Fuselage)
• Height: 18 ft 11 in (5.7 m)
• Empty weight: 23,400 lb (10,185 kg)
• Loaded weight: 26,680 lb (12,100 kg)
• Max takeoff weight: 50,000 lb (22,680 kg)
• Sling-load Capacity: 26,000 lb center hook; 17,000 lb forward/aft hook; 25,000 lb tandem
• Powerplant: 2 × Lycoming T55-GA-714A turboshaft, 4,733 hp (3,631 kW) each
• Fuel capacity: Self sealing 1,030 gallons internal, 3 additional fuel tanks can be installed in cargo area. Air refueling is also possible.

Performance

• Maximum speed: 170 knots (196 mph, 315 km/h)
• Cruise speed: 130 kt (149 mph, 240 km/h)
• Range: 400 nm (450 mi, 741 km)
• Service ceiling: 18,500 ft (5,640 m)
• Rate of climb: 1,522 ft/min (7.73 m/s)

Armament:
• up to 3 pintle mounted medium machine guns (1 on loading ramp and 2 at shoulder windows), generally 7.62 mm (0.308 in) M240/FN MAG machine guns

A Miraculous B-17 WWII Survival Story

I recently received an email about a B-17 bomber crew that overcame the odds and survived to tell about it. I would like to share it with everyone. (This happened 70 years ago.)

A mid-air collision on February 1, 1943 between a B-17 named “All American” of the 414th Squadron, 97BG and a German fighter over the Tunis dock area became the subject of one of the most famous photographs of World War II.
An enemy fighter attacking the 97th Bomb Group formation went out of control, probably with a wounded pilot, and collided into the rear fuselage of the Flying Fortress named “All American” piloted by Lt. Kendrick R. Bragg. Although the fighter broke apart, it left some pieces in the B-17. The left horizontal stabilizer of the B-17 and left elevator were completely torn away. The two right engines quit and one of the engines on the left had a serious oil pump leak. The vertical fin and the rudder were damaged and the fuselage had a 16 foot by 4 foot gash splitting it all the way to the top gunner’s turret connected only by two small parts of the airframe. The radios, electrical and oxygen systems were damaged as well.
The tail bounced, twisted, and swayed in the wind when the plane turned. All of the control cables were severed except one single elevator cable, which fortunately still worked, and the aircraft still flew on…. miraculously!
The tail gunner was trapped because there was no floor connecting the tail to the rest of the plane. The waist and tail gunners used parts of the German fighter and their own parachute harnesses in an attempt to keep the tail from ripping off and the two sides of the fuselage from splitting apart. While the crew was trying to keep the bomber from coming apart, the pilot continued on his bomb run and released his bombs over the target.
When the bomb bay doors were opened, the wind turbulence was so great that it blew one of the waist gunners into the broken tail section. It took several minutes but four crew members managed to pass him ropes from parachutes to pull him back into the forward part of the plane. They tried to do the same for the tail gunner but the tail flapped so hard that it began to break off. They found that the weight of the gunner was adding some stability to the tail section so he went back to his position.
The turn back toward England had to be very slow to keep the tail from twisting off. They actually covered almost 70 miles to make the turn home. The bomber was so badly damaged that it was losing altitude and speed and was soon alone in the sky. For a brief time “All American” was attacked by two more Me-109′s but despite the extensive damage all of the machine gunners were able to respond which drove off the fighters. The two waist gunners stood up with their heads sticking out through the hole in the top of the fuselage to aim and fire their machine guns. The tail gunner had to shoot in short bursts because the recoil was actually causing the plane to turn.
Allied P-51 fighters intercepted “All American” as it crossed over the Channel and took one of the pictures shown. They radioed to base that the empennage was “waving like a fish tail” and that the B-17 probably wouldn’t make it; boats should be dispatched to rescue the crew when they bailed out. The fighters stayed with the Fortress taking hand signals from Lt. Bragg and relaying them to the base. Lt. Bragg signaled that 5 parachutes and the spare had been “used” so five of the crew could not bail out. He made the decision that if they could not bail out safely, then he would stay with the plane and land it.

Two and a half hours after being hit, the aircraft made its final turn to line up with the runway while it was still over 40 miles away. Amazingly it descended and made an emergency landing with a normal roll-out on its own landing gear.
The ambulance was waved off when it pulled alongside the airplane because not a single member of the crew had been injured. No one could believe that the aircraft was able to fly in such a damaged condition. After the last crew member exited the fuselage the entire rear section of the aircraft collapsed onto the ground. The rugged old bird had done its job.